Grating



H. C. PIERCE April 3, 1934.

GRATING Filed Aug. 22, 1.931

@5 Gfl r INVENTOR BY 9 2 g ATTORNEY Patented Apr. 3, 1%34 StATES PATENT QFFEE Application August 22,

5 Claims.

This invention relates to gratings such as are used for closing openings in sidewalks, for stairways and platforms in power houses and in many other places, and has for its object the provision of an improved form of such gratings.

The invention is illustrated in the drawing filed herewith in which Fig. 1 shows a top view of a portion of such a grating; Fig. 2 is a sectional view of line 2-2 of Fig. 1; Fig. 3 is a similar section showing a modification; Fig. 4 is a top view of a portion of a modified form; and Fig. 5 is a sectional view on line 5-5 of Fig. 4.

To make a grating in accordance with my invention, a sheet 1 of steel or other desired material is taken and by suitable means, such as punching, openings 2-2 are made in this sheet. These openings in the preferred form shown in Fig. l have the form of a trapezoid. They are arranged in alined double rows. In each such double row the bases of the trapezoids face each other, the apexes pointing outward. One such double row is shown at 2a, a further one at 2b, and a third one at 20. The apexes 3, 3 of one row extend into the spaces between the apexes of the next row. This will be entirely clear from an inspection of Fig. 1. There are thus left between the non-parallel sides of the trapezoid strips 4, 4 of material.

The metal removed from the openings 2, 2 is not severed completely from the plate but only along the short one of the two parallel sides and along the two non-parallel sides. The longer parallel side 4 is not cut. The trapezoidal pieces of metal are bent out of their original position into one at right angles to it. As the two longer of the parallel sides of the double row 2a are adjacent to each other, these pieces when bent into their new positions will lie back to back as clearly shown at 2d, 211 in Fig. 2. The two rows, 20, 2c of these pieces of metal in effect constitute a more or less continuous beam at right angles to the original plate. Their efiect in this new position is to strengthen the plate against deformation by bending. I have found in practice that the plate is considerably strengthened in this respect by this construction. In addition, the plate has the very desirable advantage of presenting a construction which effectively prevents slipping. Not only are the portions 4, 4 narrow enough to produce this effect, but in addition the sharp edges left by the punching and the slight burring caused by the bending downward of the pieces 2d, 2d roughens the plate in a very effective manner.

The plates are preferably so punched as to have a margin 5, 5 on each side to serve as a support, for example on beams such as 6.

The construction so far described is entirely satisfactory. The further improvement disclosed in Fig. 3 however adds a further improvement.

1931, Serial No. 558,708

In this figure the downwardly extending portions 2d, 201 have their lower ends 26, 2e bent so as to interlock, thereby making the beam referred to above even more complete. The interlocking parts 26, 2e prevent the portions 201, 211 from sliding over each other so that the whole construction is substantially like a real beam.

In Figs. 4 and 5 I illustrate a modification in which the pieces 2d, 2d and the openings 2, 2 are triangular in shape instead of trapezoidal. It is thought that this is entirely clear from the above description and from an inspection of the two figures and no further description is required.

It will be perfectly clear that the inventive idea disclosed hereinabove can be varied more or less without departing from its spirit.

I claim:

1. As an article of manufacture, a metallic sheet having a plurality of trapezoidal holes, said holes being alined in two rows, the holes of each row being alined with the longer parallel sides in line, and the longer parallel sides of one row being adjacent to but staggered relatively to those of the other row, and metallic pieces integral with the sheet and extending at right angles from it along each longer parallel side, those of one row being back to back with those of the other row, but staggered relatively to them and overlapping them.

2. An article of manufacture in accordance with claim 1, the tips of said metallic pieces being bent to interlock mutually.

3. An article of manufacture having a plurality of double rows of holes and metallic pieces according to claim 1, the tips of each row of each pair being bent to interlock with each other.

4. An article of manufacture having a plurality of double rows of holes and metallic pieces according to claim 1, all of said rows being parallel.

5. As an article of manufacture, a' metallic sheet having a plurality of polygonal holes, said holes being arranged in a plurality of double rows, the holes of each row being alined with one side of each in line with one side of the others, the alined sides of one row of each double row being adjacent to but staggered relatively to those of the other, and metallic pieces integral with the sheet and extending at right angles from it along the alined sides of the holes, those of each double row being back to back, staggered and overlapping.

HARRY C. PIERCE. 

